Electrically conductive foil tapes have numerous constructions and have conventionally been formed using various methods. For example, in one construction, an electrically conductive adhesive tape can be formed by dispersing finely divided silver in a pressure sensitive adhesive and coating the adhesive on an electrically conductive foil backing. In another construction, a conductive tape is formed with a monolayer of large conductive particles on the pressure sensitive adhesive. In yet another embodiment, an electrically conductive foil backing is embossed to have a plurality of closely spaced electrically conductive projections that extend almost through the layer of adhesive. One characteristic common to all of these constructions is that they do not provide good conformability to various adherents because of the stiffness of the foil backing.
There is an increasing demand for thin, conductive double-sided tapes and thin, conductive flexible single-sided foil tapes, both of which can provide good conformance, flexibility and strength. This is in part because connections to edged curvatures or various rough surfaces are becoming more important for many electronic uses of the conductive tapes and the tapes are required to conform to these topographical features. However, when the tape is fabricated to improve conformance and flexibility via a thinner adhesive or foil layer, the tape becomes difficult to handle because of its reduced strength.
There has also been an increasing demand for thinner conductive single-sided tapes which can provide good workability and handling properties. This is generally because most foil tapes are easily curled when the release liner is removed from the adhesive. The curling may become more severe as the foil backing become thinner.